Scotland’s cloud may need its own power station. It has become unexpectedly solid.

The cloud, it turns out, is not a cloud. It is an industrial estate with an appetite, a cooling system and the sort of extension lead that makes a planning committee sit up very straight. Holyrood’s Climate Action Committee began taking evidence on hyperscale data centres on Thursday, after campaigners warned that one very large site could have “national-level consequences” for Scotland’s energy and climate plans.

That warning is evidence submitted to an inquiry. It is not a committee finding, a planning decision or proof that Scotland is about to dim the lights so a chatbot can finish its sentence. Scotland currently has no hyperscale data centres, according to the Parliament’s inquiry page. MSPs are examining what might happen if proposals now circling the country become steel, cables and invoices.

The proposal doing most of the heavy lifting in this seminar is Chapelcross in Dumfries and Galloway. The developer describes a campus with up to 960 megawatts of capacity, often rounded to one gigawatt in public discussion. That is the point at which the word “cloud” begins to feel like a small prank played on the electricity grid.

Friends of the Earth Scotland told MSPs that Chapelcross could use about nine terawatt hours of electricity a year. An earlier motion lodged in the Scottish Parliament estimated seven terawatt hours and said that was equivalent to the annual electricity use of more than two million homes. Those are projections built from different assumptions, not meter readings from an operating site. The honest answer is therefore a range, followed by a very large question mark and the Professor refusing to let anyone erase either number from the board.

Campaigners also argued that a project of this scale could force difficult choices about new generation, grid connections and who ultimately pays for them. A data centre can support investment and computing services, but its electricity demand does not arrive wearing a little badge marked “private matter”. It turns up in the same national system as homes, hospitals, trains and everything else that becomes unpopular when the socket stops cooperating.

The Scottish Government has said it intends to publish planning guidance for data centres before the end of 2026. Ministers have also told Parliament that applications above 50 megawatts must be notified to them and would require environmental impact assessment, and that no related planning decisions were expected before the guidance was produced.

This first evidence session did not settle the case. The committee says it will hear from technical specialists and witnesses on sustainability, water, mitigation and other practical questions. Its call for views remains open until 15 November, which is useful because a national infrastructure argument should probably include more than one morning of people discovering that the internet has plumbing.

So the immediate development is scrutiny, not construction. Scotland is being asked how much physical country it is willing to put behind the digital one, and under what rules. The Professor’s preliminary conclusion is modest: if your cloud requires its own turbine, several reservoirs and a cable the width of regret, it should at least have to show its working.